[Payments] Display the shipping option error alongside the address

components/payments/content/payment_request_spec.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/payments/content/payment_request_spec.h"
 
 #include <utility>
 
 #include "base/logging.h"
 #include "components/payments/core/payment_method_data.h"
@@ skipping 148 matching lines @@
                                              &supported_card_networks_,
                                              &basic_card_specified_networks_);
   supported_card_networks_set_.insert(supported_card_networks_.begin(),
                                       supported_card_networks_.end());
 }
 
 void PaymentRequestSpec::UpdateSelectedShippingOption() {
   if (!request_shipping())
     return;
 
+  selected_shipping_option_error_.clear();
   // As per the spec, the selected shipping option should initially be the last
   // one in the array that has its selected field set to true.
   auto selected_shipping_option_it = std::find_if(
       details().shipping_options.rbegin(), details().shipping_options.rend(),
       [](const payments::mojom::PaymentShippingOptionPtr& element) {
         return element->selected;
       });
   if (selected_shipping_option_it != details().shipping_options.rend()) {
     selected_shipping_option_ = selected_shipping_option_it->get();
   } else {
     // It's possible that there is no selected shipping option.
-    // TODO(crbug.com/710004): Show an error in this case.
+    if (!details().error.empty())
+      selected_shipping_option_error_ = details().error;
     selected_shipping_option_ = nullptr;
   }
 }
 
 void PaymentRequestSpec::NotifyOnSpecUpdated() {
   for (auto& observer : observers_)
     observer.OnSpecUpdated();
   if (observer_for_testing_)
     observer_for_testing_->OnSpecUpdated();
 }
 
 CurrencyFormatter* PaymentRequestSpec::GetOrCreateCurrencyFormatter(
     const std::string& currency_code,
     const std::string& currency_system,
     const std::string& locale_name) {
   if (!currency_formatter_) {
     currency_formatter_.reset(
         new CurrencyFormatter(currency_code, currency_system, locale_name));
   }
   return currency_formatter_.get();
 }
 
 }  // namespace payments